Furnace



Sept. 20, 1932.

C. E. LUCKE FURNACE Filed Aug. 7, 1928 5 Sheets-Sheet 1 2 5 ATTORNEYS c. E. LUCKE Sept. 20, 1932.

' FURNACE Filed Aug. 7-, 1928 5 Sheets-Sheet 5 INVENTOR Q M g ATTORQEB Patented Sept. 20, 1932 UNITED STATES PATENT OFFICE CHARLES E. LUCKE, OF N YORK, N. Y., ASSIGNOR TO FULLER LEHIGH COMPANY, OF FULLERTON, PENNSYLVANIA, A CORPORATION OF DELAWARE FURNACE Application filed August 7, 1928. Serial No. 297,955.

This invention relates to a novel form of furnace and will be best understood from the following description and the accompanying drawings. In the drawings, in which I have shown selected embodiments of the invention;

Fig. 1 is a vertical sectional view through a furnace and boiler showing my invention applied thereto.

Fig. 2 is a horizontal sectional view through the furnace shown in Fig. 1, and showing my invention in diagrammatic form applied to the furnace.

Fig. 3 is a vertical sectional view through the slag-tapping opening.

Fig. 4 is a detailed View illustrating one form which the heating element may take.

Fig. 5 is a fragmentary sectional view through the furnace floor showing the type of heating element illustrated in Fig. 4.

Fig. 6 shows in fragmentary form a different form of-heating element.

Fig. 7 is a view corresponding to Flg. 5, and showing the form of heating element illustrated in Fig. 6.

In operating a furnace using a slag-forming fuel, it has been suggested that the floor of the furnace should support a bed of slag in a molten condition, into which the slag in the fuel may fall from the combustion chamber or intowhich it may flow from the walls of the chamber. The object of the invention is to insure that the slag shall remain in the molten condition referred to. This molten condition is desirable for several reasons, one of which is that it facilitates the disposal of the slag which, when it is maintained in its molten condition, can be tapped from the furnace, thus avoiding troubles which arise when it hardens.

I have shown my invention as applied to a furnace having a combustion chamber 1 formed of walls comprising cooling tubes 2 and blocks 3 secured to said tubes. Above the combustion chamber is shown a boiler indicated at 4 and which may be of any suitable form. The tubes 2 may be connected to the boiler and may be used to heat either water or steam as desired. For the purposes of illustration, I have shown the furnace burning pulverized coal-which may be introduced into the furnace from a plurality of burners 5.

The fuel from these burners is burned in the combustion chamber and the hot gases therefrom arise and pass over the boiler tubes in the usual way, but in doing so slag is usually formed and drops to the bottom of the furnace. The heat from the burning fuel may be sufiicient to maintain the slag accumulating on the floor of the furnace in a molten condition, in which condition it may be tapped through spout 6. The opening in the furnace wall communicating with the spout may be normally closed by a gate 7 shown in Fig. 3, but omitted from Fig. 2 for the sake of clearness.

According to my invention, the floor of thefurnace supports a bed 8 of refractory material which may be, and preferably is, an accumulation of slag from the slag-forming fuel burned in the furnace, and I maintain this refractory material in a molten pool by supplementing the heat from the burners by heat from a plurality of heating elements preferably mounted in the refractory materlal forming the floor. I shall hereinafter refer to this refractory material as slag.

The heating elements referred to may conveniently be made in the form of electrical, resistance elements 9, and in Figs. 4, 5, 6 and 7, I have shown two forms which such elements may take. In Figs. 4 and 51 have shown a carbon tube 10 forming one electrode of the element, the other electrode being formed by a carbon rod 11 disposed in the tube 10. Between the two electrodes is disposed a suitable electrical resistance such as granular or pulverized carbon 12. In Figs. 6 and 7 I have shown a refractory tube 13 filled with granular or pulverized carbon 14 forming an electrical resistance between electrodes 15 disposed at opposite ends of the tube. 1

In both forms, the electrodes are formed with suitable connections 16 indicated diagrammatically in Fig. 2 as being connected to burners may be supplemented to a sufiicient extent to maintain the bed of slag on the floor 18 in a molten condition. As pointed out above, it is desirable to have the slag in such a condition that it may be readily tapped from the furnace, and the heating elements provide any additional heat which may be necessary to bring the slag to a molten condition which will permit tapping.

The heating elements are particularly useful when the furnace'is not running at its maximum temperature, and/ or when the slag has a high fusing temperature. The heating elements will normally be used only for short intervals, when it is desired to tap the slag, and then the current may be turned off. If desired the bed 8 may be previously deposited on the floor, or the slag formed by burning the fuel may be permitted to accumulate and thus form the bed.

CHARLES E. LUGKE.

heat said bed.

Moreover, the current may be supplied to the heating elements when the furnace is first started up, in order to help in quickly raising a furnace to the proper temperature for combustion, and then it may be turned off if orwhen the temperature can be maintained sufficiently high by the heat from the burning fuel alone.

The amount of heat furnished by the elements 9 is small in relation to the amount of heat supplied by the furnace, and it is only used at intervals and for relatively short times. Therefore, it is possible to employ electric heating elements with economy.

-I claim 1. In combination, a furnace having a bed of slag on the floor thereof, means to burn fuel in said furnace, and electrical heating elements adapted to heat said bed substantially throughout its extent.

2. In combination, a furnace'having a substantially horizontal bed of refractory material, means to burn a fuel in said furnace,

and additional means to heat said bed substantially throughout its extent.

3. In combination, a furnace having a bed of refractory material, means to burn a fuel in said furnace, and heating means disposed in said bed and adapted to bring it to a molten condition.

4. In combination, a furnace having means to burn a slag-forming fuel and having asubstantially horizontal bed on the floor thereof formed at least in part by the slag from said fuel, and means in additional to Ehe burning means to heat said floor substan ially throughout its extent.

. 5. In combination, a furnace having a bed (if slag on the floor thereof, means to burn fuel in said furnace, and electrical heating elements disposed in said bed.

6. In combination, a furnace having a bed of slag on the floor thereof, means to burn 

